Here is the crash report:
---- Minecraft Crash Report ----

WARNING: coremods are present:
TLSkinCapeHookLoader (tlskincape_1.12.2-1.4.jar)
FP2MixinLoader (fp2-0.0.1.381-1.12.2.jar)
Contact their authors BEFORE contacting forge

// Would you like a cupcake?

Time: 5/19/21 1:28 PM
Description: There was a severe problem during mod loading that has caused the game to fail

net.minecraftforge.fml.common.LoaderExceptionModCrash: Caught exception from FarPlaneTwo (fp2)
Caused by: java.lang.IllegalStateException: unable to enable stencil buffer!
at net.daporkchop.lib.common.util.PValidation.checkState(PValidation.java:358)
at net.daporkchop.fp2.client.FP2Client.preInit(FP2Client.java:64)
at net.daporkchop.fp2.FP2.preInit(FP2.java:66)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at net.minecraftforge.fml.common.FMLModContainer.handleModStateEvent(FMLModContainer.java:637)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at com.google.common.eventbus.Subscriber.invokeSubscriberMethod(Subscriber.java:91)
at com.google.common.eventbus.Subscriber$SynchronizedSubscriber.invokeSubscriberMethod(Subscriber.java:150)
at com.google.common.eventbus.Subscriber$1.run(Subscriber.java:76)
at com.google.common.util.concurrent.MoreExecutors$DirectExecutor.execute(MoreExecutors.java:399)
at com.google.common.eventbus.Subscriber.dispatchEvent(Subscriber.java:71)
at com.google.common.eventbus.Dispatcher$PerThreadQueuedDispatcher.dispatch(Dispatcher.java:116)
at com.google.common.eventbus.EventBus.post(EventBus.java:217)
at net.minecraftforge.fml.common.LoadController.sendEventToModContainer(LoadController.java:219)
at net.minecraftforge.fml.common.LoadController.propogateStateMessage(LoadController.java:197)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at com.google.common.eventbus.Subscriber.invokeSubscriberMethod(Subscriber.java:91)
at com.google.common.eventbus.Subscriber$SynchronizedSubscriber.invokeSubscriberMethod(Subscriber.java:150)
at com.google.common.eventbus.Subscriber$1.run(Subscriber.java:76)
at com.google.common.util.concurrent.MoreExecutors$DirectExecutor.execute(MoreExecutors.java:399)
at com.google.common.eventbus.Subscriber.dispatchEvent(Subscriber.java:71)
at com.google.common.eventbus.Dispatcher$PerThreadQueuedDispatcher.dispatch(Dispatcher.java:116)
at com.google.common.eventbus.EventBus.post(EventBus.java:217)
at net.minecraftforge.fml.common.LoadController.distributeStateMessage(LoadController.java:136)
at net.minecraftforge.fml.common.Loader.preinitializeMods(Loader.java:629)
at net.minecraftforge.fml.client.FMLClientHandler.beginMinecraftLoading(FMLClientHandler.java:252)
at net.minecraft.client.Minecraft.func_71384_a(Minecraft.java:467)
at net.minecraft.client.Minecraft.func_99999_d(Minecraft.java:378)
at net.minecraft.client.main.Main.main(SourceFile:123)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at net.minecraft.launchwrapper.Launch.launch(Launch.java:135)
at net.minecraft.launchwrapper.Launch.main(Launch.java:28)

A detailed walkthrough of the error, its code path and all known details is as follows:

-- System Details --
Details:
Minecraft Version: 1.12.2
Operating System: Windows 7 (amd64) version 6.1
Java Version: 1.8.0_291, Oracle Corporation
Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
Memory: 128280640 bytes (122 MB) / 436207616 bytes (416 MB) up to 6375342080 bytes (6080 MB)
JVM Flags: 8 total; -Xmn128M -Xmx6067M -XX:+UnlockExperimentalVMOptions -XX:+UseG1GC -XX:G1NewSizePercent=20 -XX:G1ReservePercent=20 -XX:MaxGCPauseMillis=50 -XX:G1HeapRegionSize=32M
IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
FML: MCP 9.42 Powered by Forge 14.23.5.2855 Optifine OptiFine_1.12.2_HD_U_G5 7 mods loaded, 7 mods active
States: 'U' = Unloaded 'L' = Loaded 'C' = Constructed 'H' = Pre-initialized 'I' = Initialized 'J' = Post-initialized 'A' = Available 'D' = Disabled 'E' = Errored

| State | ID                         | Version       | Source                            | Signature                                |
|:----- |:-------------------------- |:------------- |:--------------------------------- |:---------------------------------------- |
| LCH   | minecraft                  | 1.12.2        | minecraft.jar                     | None                                     |
| LCH   | mcp                        | 9.42          | minecraft.jar                     | None                                     |
| LCH   | FML                        | 8.0.99.99     | forge-1.12.2-14.23.5.2855.jar     | e3c3d50c7c986df74c645c0ac54639741c90a557 |
| LCH   | forge                      | 14.23.5.2855  | forge-1.12.2-14.23.5.2855.jar     | e3c3d50c7c986df74c645c0ac54639741c90a557 |
| LCH   | forgerocks                 | 6.13.3-1.12.2 | ForgeRocks-6.13.3-1.12.2-full.jar | None                                     |
| LCE   | fp2                        | 0.0.1.381     | fp2-0.0.1.381-1.12.2.jar          | None                                     |
| LC    | tlauncher_custom_cape_skin | 1.4           | tlskincape_1.12.2-1.4.jar         | None                                     |

Loaded coremods (and transformers): 

TLSkinCapeHookLoader (tlskincape_1.12.2-1.4.jar)
gloomyfolken.hooklib.minecraft.PrimaryClassTransformer
FP2MixinLoader (fp2-0.0.1.381-1.12.2.jar)

GL info: ' Vendor: 'NVIDIA Corporation' Version: '4.6.0 NVIDIA 391.35' Renderer: 'GeForce GTS 450/PCIe/SSE2'
OptiFine Version: OptiFine_1.12.2_HD_U_G5
OptiFine Build: 20210124-142939
Render Distance Chunks: 8
Mipmaps: 4
Anisotropic Filtering: 1
Antialiasing: 0
Multitexture: false
Shaders: null
OpenGlVersion: 4.6.0 NVIDIA 391.35
OpenGlRenderer: GeForce GTS 450/PCIe/SSE2
OpenGlVendor: NVIDIA Corporation
CpuCount: 2

it's crashed while loading the world without optifine and crashed while loading the game (before main menu showed up) with optifine
is there anyway to fix this?

remove fp2, then launch the game with optifine. disable fast render and antialiasing, then re-add fp2 and the game will launch fine.

remove fp2, then launch the game with optifine. disable fast render and antialiasing, then re-add fp2 and the game will launch fine.

i have same problem, but my "fast render" and "antialiasing" were already disabled, what to do? my minecraft crashes while loading the world WITH optifine

ohh, now my world launched(with fp2) but it(fp2) work and dont work at the same time
button is here

but:

HOLY SH*T

okaay, it works, but bad

now i know why this "pre-pre-pre alpha"
but still its not very bad, i think in future its going to be very cool